Field of the Invention
The disclosed invention relates to brake cylinders and, more particularly, to venting arrangements for a non-pressure head end of a brake cylinder.
Description of Related Art
Venting arrangements are typically provided on a non-pressure head of brake cylinders to permit the piston to extend without building pressure within the brake cylinder during extension or application of the cylinder. Furthermore, the vent also ensures proper release of the cylinder after extension by allowing atmospheric air to enter the non-pressure head end of the brake cylinder.
As shown in FIGS. 1-4, a known brake cylinder 10 generally includes a cylinder body 12 having an annular flange 14, a non-pressure head 20 comprising an annular flange 21, and a head portion 23 extending from the annular flange 21. Mounting feet 25 are provided on one side of the cylinder body 12 for securing the cylinder 10 to a structure, such as a freight car. A vent 22 is typically provided in the head portion 23 of the non-pressure head 20 such that the vent 22 is oriented downward to prevent drawing moisture into the brake cylinder when the cylinder 10 is released during inclement weather. Further, the brake cylinder 10 may be mounted to a freight car in any of four orientations, with the mounting feet 25 facing generally left (FIG. 1), generally up (FIG. 2), generally down (FIG. 3), and generally right (FIG. 4). Therefore, the orientation of the vent 22 with respect to the mounting feet 25 generally must be predetermined (e.g., in advance) by the end-user. Once the end-user has received the brake cylinder assembly, further modifications to the orientation of the vent 22 are unavailable and the end-user must mount the brake cylinder to the freight car or other structure in its predetermined mounting orientation.
It is known to include vent structures in a non-pressure head as disclosed by U.S. Pat. No. 1,939,845 to Farmer. This patent discloses a brake cylinder having a breather nozzle positioned on a flange portion of the non-pressure head. The breather nozzle has a passage through the nozzle having communication with the interior of a filter element and the atmosphere. In a more recent example, U.S. Pat. No. 7,303,053 to McCurdy, Jr. discloses a non-pressure head having a flange and a head portion. A portion of the flange is raised to provide a drainage duct or vent.
U.S. Pat. No. 7,306,078 to Fish discloses a composite brake cylinder having a blind end cap that may be oriented in any circular position.
U.S. Pat. No. 1,939,845 to Farmer, noted previously, and U.S. Pat. No. 1,615,370 also to Farmer, each disclose a brake cylinder in which vent structures are provided in a flange of the cylinder. In the Farmer '845 patent, a breather nozzle is in fluid communication with a non-pressure head and, in the Farmer '370 patent, a vent passage is provided in a non-pressure head adjacent a flange structure.
U.S. Pat. No. 3,101,219 to Herrara and U.S. Pat. No. 3,613,515 to Swander, Jr. disclose similar vent arrangements in which a series of vents are provided in an endwall of a piston cylinder.
U.S. Pat. No. 3,187,642 to Cruse discloses an axially-centered vent arrangement.
U.S. Pat. No. 2,177,767 to Campbell discloses an air brake cylinder with a vent with an accompanying filter disk.
Finally, U.S. Pat. No. 5,722,311 to Pierce et al. and U.S. Pat. No. 6,029,447 to Stojic et al. disclose spring brake actuators. The Stojic patent discloses an end-wall vent opening or passageway and the Pierce patent discloses the use of an elastomeric one-way vent.